1. Field of the Invention.
This invention is in the field of pipe coatings and protective wrappings. More particularly it is concerned with the application to long cylindrical tubes or pipes, of uniform circumferential coatings with selected materials, and the protection of the coatings by means of sealed wrappings with films of plastic, paper, etc. Still more particularly this invention is concerned with the simultaneous application of a continuous flexible plastic or synthetic film or wrap to a cylindrical object such as a pipe or conduit, and the injection of a circumferential coating of a selected material in the annular space between the object and the film.
2. Prior Art
Pipelines are typically coated with a helically wound wrap of a chemically treated paper or similar protective material. The wrap is sometimes bound to the pipe by an undercoating of adhesive or similar material applied to the pipe by brush, or the like. This process is only workable when the applied coating is very thin, of the proper nature, and of the proper consistency. If thick coatings are applied by this method, pressure of the wrapping tends to distort the thickness and character of the coating, with unsatisfactory results.
The prior art references made of record and noted to the Patent and Trademark Office in said prior related Patents and Applications is incorporated by reference herein.